The present invention relates to a low-cost communication system for vehicles to permit the exchange of data between vehicles as they travel along a highway.
When driving a vehicle, such as an automobile or truck on a highway, the observation of driving conditions tends to be up to each individual driver. Of course, drivers can receive safety information from public radio stations or even from other drivers through two-way radios such as citizens band radios available in the United States. However, both the safety of the situations in which drivers find themselves and the degree satisfaction or dissatisfaction which driving gives them is directly dependent upon the ability of the driver to collect and interpret necessary data, including listening to reports on the radio, and then be able to take the appropriate action within a required response time. Unfortunately, since the human driver does not always collect and interpret necessary data appropriately, many traffic accidents occur on the highways today because of human error, or near misses occur which tends to give the driver an intense sense of dissatisfaction with the driving experience.
Prior art systems have attempted to provide mechanisms for transferring data between automobiles traveling on highways. U.S. Pat. No. 4,706,086 issued to E. Panizza on Nov. 10, 1987 discloses a system for signaling between vehicles. In Panizza, sensors are used to detect various vehicle parameters. A processing unit processes the sensor data to determine the vehicle environment and to create a signal message about the environment. This message is then sent to one or more vehicles traveling in the opposite direction via infrared or directional radio frequency transmission. These vehicles, if equipped with the signaling system, will process and retransmit the message to vehicles traveling in the same direction as the first vehicle. Hence, this system relies upon the presence of vehicles traveling in the opposite direction to pass messages to trailing vehicles and also relies upon a clear transmission path between vehicles in opposite lanes of the highway. Many U.S. highways are constructed such that opposing lanes are obstructed from each other, so the signaling system disclosed by Panizza may not work on such highways.
Another signaling system is disclosed in U.S. Pat. No. 5,589,827 issued to M. Scurati on Dec. 31, 1996. Scurati discloses a system where vehicle information such as speed, acceleration, location, etc. is passed from a lead vehicle to a following vehicle in a chain of vehicles by radio frequency transmission. The system relies upon tight synchronization of transmissions so that the transmission between the vehicles will not interfere with one another. This synchronization is optimally obtained from master stations providing synchronization data to all vehicles within a stretch of highway. Degraded synchronization results when the transmit and receive systems in each vehicle self-synchronize, with the possibility that some transmissions may interfere with each other. The system disclosed by Scurati transfers information from leading vehicles to following vehicles, and does not provide the capability to transfer information from following vehicles to leading vehicles or to vehicles traveling in the opposite direction.
Still another signaling system is disclosed in U.S. Pat. No. 5,424,726 issued to B. Beymer on Jun. 13, 1995. Beymer discloses a system that generally transmits vehicle information rearward by a radio frequency transmitter mounted on the rear of a lead vehicle received by a receiver mounted on the front of a following vehicle. Beymer also allows for the transmission of information forward from a following vehicle to a lead vehicle by using a forward-mounted radio frequency transmitter and a rear-mounted receiver. However, the system disclosed by Beymer relies upon highly directional transmitters to ensure that only vehicles in a substantially linear chain will be in communication. Thus, vehicles in adjacent or opposing lanes will not receive vehicle information.
Prior art systems are characterized by the use of additional components to achieve data communication between vehicles. These additional components lead to higher cost, more maintenance, and less consumer acceptance of vehicles equipped with such systems. System that rely upon radio frequency transmission are subject to interference from other radio frequency sources and possible regulatory concerns. Thus, there exists a need in the art for a low cost, interference-resistant system for communicating between vehicles.
The present invention provides low-cost, communication links between vehicles, such as private, commercial, law enforcement automobiles and trucks or even boats and trains, preferably using existing vehicular optical components combined with low cost sensors. By encoding information onto vehicle components such as headlights and taillights at appropriate data rates (less than 1 KHz for some applications), information can be transmitted between vehicles. The modulated light is sensed and decoded on board the vehicle using detectors and the encoded data need not be directly perceived by the driver. The data stream can provide critical information to the driver, including collision avoidance warnings, information about the presence of am emergency vehicle, etc., in addition to information about neighboring vehicles.
A typical application of the system is to automatically address vehicle spacing. Position and velocity information for a vehicle is obtained from sensors or data sources such as Global Positioning Satellite receivers. The inter vehicle communication system provides this information to surrounding vehicles, which then process the information to determine vehicle spacing. If a forward vehicle determines that it is being followed too closely, the forward vehicle""s brake lights might flash rapidly (as if the brakes were pumped) to alert the offender of a possible safety hazard. At the same time, proximity alert information may be sent via the inter vehicle communication system from the forward vehicle to the trailing vehicle to result in an alarm or warning message in the offender""s vehicle. This system effectively takes the driver in the forward vehicle out of the loop, by automatically signaling the tailgating vehicle.
Automatic inter vehicle communication provides additional advantages such as reduction in driver stress, safer lane changes, reduced travel time, and improved route planning. The advantages of the present invention are further enhanced by supporting communication among multiple vehicles. Small corner-cubes or retroreflector arrays (on either or both vehicles) can be used to relay information back to other vehicles for range-Doppler or other accident avoidance information (via time-of-flight measurements). The present invention can also be used to propagate emergency vehicle warnings among multiple vehicles. The use of new gas discharge lamps for headlights, as well as LEDs and neon discharge taillights provides an opportunity for very high data rates with minimal modification to existing hardware on vehicles.
An object of the present invention is to provide an inter vehicle communication system for communicating between vehicles using data sources, data sensors, and vehicle sensors on each vehicle and a central processing unit on each vehicle for processing the data passed between vehicles. The data sensors, preferably optical, will receive data messages from other vehicles with the inter vehicle communication system. The central processing unit will weight this received data according to its time of generation, distance from its source, and other factors. The central processing unit will then process the weighted data along with onboard data sensed from the vehicle by vehicle sensors. The onboard data may include speed, rate of the acceleration/deceleration, steering wheel angle, yaw rate, intended lane change, braking, location, and other vehicle information. The central processing unit will then provide control information to the vehicle. This control information may include specific control commands for vehicle operation, or alerts to the vehicle operator. The central processing unit will also create a data message for transfer to other vehicles. The message will be sent to other vehicles using data sources, again preferably optical.
In operation, the central processing unit on the first vehicle will control the transfer of information to a second vehicle concerning the speed, rate of the acceleration/deceleration, steering wheel angle, yaw rate, intended lane change, braking, location, and other vehicle information about the first vehicle using a source or sources, preferably optical, on the first vehicle. The second vehicle will receive the information via a sensor or sensors, again preferably optical, and the central processing unit on the second vehicle will process the received information, apply weights to the information, alert the vehicle operator or control vehicle operation, and create messages to be sent to other vehicles.
An additional object of the present invention is to provide a method for relaying emergency information among multiple vehicles using inter vehicle communication to transfer the information from one vehicle to the next.
A first embodiment of the present invention provides an inter vehicle communication system for communicating between a plurality of vehicles, in which each vehicle contains an apparatus comprising: a central processing unit; data sources coupled to the central processing unit; data sensors coupled to the central processing unit; and vehicle sensors coupled to the central processing unit, in which the central processing unit processes data received from the data sensors and from the vehicle sensors, calculates information weights for the data, generates a transmit message based on the data, and provides the transmit message to the data sources.
Another embodiment of the present invention provides a method of inter vehicle communication comprising the steps of: sensing vehicle information; creating a transmit vehicle message; transmitting the transmit vehicle message; receiving the transmit vehicle message at a receive vehicle; sensing receive vehicle information; extracting vehicle information from the transmit vehicle message; weighting the vehicle information to create weighted vehicle information; processing the the receive vehicle information and the weighted vehicle information to determine inter vehicle status; and providing control information to a receive vehicle control system based on the inter vehicle status.
Another embodiment of the present invention provides a method of inter vehicle communication between multiple vehicles comprising the steps of: sensing current transmit vehicle information; creating a message for each transmit vehicle; transmitting the message; receiving the message from each transmit vehicle at a receive vehicle; extracting current transmit vehicle information from the message; creating weighted transmit vehicle information from the received vehicle information; reading receive vehicle information from receive vehicle sensors; and processing the weighted transmit vehicle information and receive vehicle information to determine multiple vehicle status.
Another embodiment of the present invention provides an inter vehicle communication system comprising: one or more light sources on a first vehicle, such that the light sources radiate light in a spectrum visible to the human eye; means for modulating the light radiated from the light sources with data; one or more light sensors on a second vehicle, such that the light sensors detect the modulated light from the first vehicle; and means for demodulating the detected light signal to extract the data. The light sources may include headlights, taillights, side lights, emergency beacons, or other visible light sources. Use of such light sources allows the lights sources to have a dual use. The first and primary use is for visual illumination or warning, while the second use is the provision of a mechanism for inter vehicle communication. The means for modulating the light includes electrical modulators that change the voltage or current applied to the light source based upon the data, liquid crystal light valves that cover the light source and transmit light based upon the data, or liquid crystal light valves that cover reflective elements such that light directed onto the elements with be reflected based upon the data. Lights sensors such as photo detectors can be used, and the means for demodulating the detected signal may comprise demodulator circuits well known in the art.